drm/panel-lg-lg4573: Fix dotclock

The currently listed dotclock disagrees with the currently
listed vrefresh rate. Change the dotclock to match the vrefresh.

Someone tell me which (if either) of the dotclock or vreresh is
correct?

Cc: Heiko Schocher <hs@denx.de>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200302203452.17977-7-ville.syrjala@linux.intel.comReviewed-by: Heiko Schocher <hs@denx.de>

drivers/gpu/drm/panel/panel-lg-lg4573.c

@@ -197,7 +197,7 @@ static int lg4573_enable(struct drm_panel *panel)
 }
 
 static const struct drm_display_mode default_mode = {
-	.clock = 27000,
+	.clock = 28341,
 	.hdisplay = 480,
 	.hsync_start = 480 + 10,
 	.hsync_end = 480 + 10 + 59,